共查询到20条相似文献,搜索用时 78 毫秒
1.
2.
3.
4.
5.
6.
物理是一门以实验为基础的科学,它把深刻的科学道理蕴藏在各种丰富多彩妙趣横生的物理实验和物理现象中.初中物理实验教学的形式主要有演示实验、学生实验和课外实验等.所有实验中,演示实验所占的比重最大. 相似文献
7.
8.
9.
以"物理演示实验"为主题和关键词,检索并收集CNKI中2007-2017年的相关文献,应用Citespace对其研究作者、研究机构、研究热点进行图谱绘制及分析,揭示物理演示实验研究发展演进过程.分析结果表明:发表论文总数较少,研究多建立在"学缘"基础上,高校为目前物理演示实验研究的核心机构团队,频次和中心性排名前20的关键词集中在物理演示实验教学领域,但较为笼统.建议增加物理演示实验的研究,增强校际合作,增加中学生和中学教师走进大学物理演示实验基地;微观与宏观相结合,结合时代背景和技术条件创新与整合教学模式、教学设计及课堂教学. 相似文献
10.
物理演示实验在教学中占有十分重要的地位 ,它能帮助学生理解物理现象 ,掌握物理概念和规律 ;它还能向学生提供示范 ,培养学生的实验素质和动手能力 .下面就目前中专物理演示实验中出现的一些现象提出自己的看法 .1 轻实验过程重实验结论这主要表现在把演示实验教学的重点放在 相似文献
11.
12.
验证相对论效应实验装置能够形象直观而又方便地验证快速电子的能量与动量的相对论关系.近年来的重新设计和改进在保留原有优点和特色的基础上改进了原装置的不足,突出了综合型、设计型的特点,真正达到了一机多用的目的,符合面向二十一世纪物理实验教学改革的趋势和方向. 相似文献
13.
14.
15.
16.
Roman U. Sexl 《General Relativity and Gravitation》1970,1(2):159-180
Geo-chronometric conventionalism (GC) is shown to be part of a more general thesis, universal conventionalism, stating that coordinative definitions are needed in order to compare two measurements of any physical quantity at different space-time points. Two fully elaborated examples of the use of non-standard coordinative definitions in physics are given, demonstrating that the use of these definitions can actually simplify the physical formalism.Finally, we find that not only the metric of space-time is conventional (even non-Riemanian metrics are admissible), but also its topology and number of dimensions. 相似文献
17.
One of the oldest open questions in semiconductor physics is the origin of the small splittings of the neutral acceptor ground state in silicon which lead to a distribution of doublet splittings rather than the fourfold-degenerate state of Gamma(8) symmetry expected in the absence of perturbations. Here we show that these acceptor ground state splittings are absent in the photoluminescence spectra of acceptor bound excitons in isotopically purified 28Si, demonstrating conclusively the surprising result that the splittings previously observed in natural Si result from the randomness of the Si isotopic composition. 相似文献
18.
Employing the algebraic framework of local quantum physics, vacuum states in Minkowski space are distinguished by a property of geometric modular action. This property allows one to construct from any locally generated net of observables and corresponding state a continuous unitary representation of the proper Poincaré group which acts covariantly on the net and leaves the state invariant. The present results and methods substantially improve upon previous work. In particular, the continuity properties of the representation are shown to be a consequence of the net structure, and surmised cohomological problems in the construction of the representation are resolved by demonstrating that, for the Poincaré group, continuous reflection maps are restrictions of continuous homomorphisms. 相似文献
19.
In chemistry and physics symmetry principles are all important, for example, leading to the selection rules governing optical transitions. We have investigated the influence of the molecular symmetry on the surface potential landscape of molecules in the limit of weak molecule-substrate binding. For this purpose, the induced lateral motion of Cu(II)-tetraazaphthalocyanine molecules, for which four symmetry distinct isomers exist, on NaCl(100) was studied by scanning tunneling microscopy. This nonthermal diffusion induced by inelastic excitations is found to be qualitatively different for all four symmetry distinct isomers, demonstrating that symmetry governs the surface potential landscape. 相似文献
20.
Adiabatic evolution, an important dynamical process in a variety of classical and quantum systems providing a robust way of steering a system into a desired state 1 - 5 , was introduced only recently to frequency conversion 6 - 9 . Adiabatic frequency conversion allowed the achievement of efficient scalable broadband frequency conversion 8 , 9 and was applied successfully to the conversion of ultrashort pulses, demonstrating near‐100% efficiency for ultrabroadband spectrum 10 - 16 . The underlying analogy between undepleted pump nonlinear processes and coherently excited quantum systems was extended in the past few years to multi‐level quantum systems, demonstrating new concepts in frequency conversion, such as complete frequency conversion through an absorption band 17 - 20 . Additionally, the undepleted pump restriction was removed, enabling the exploration of adiabatic processes in the fully nonlinear dynamics regime of nonlinear optics 21 - 26 . In this article, the basic concept of adiabatic frequency conversion is introduced, and recent advances in ultrashort physics, multi‐process systems, and the fully nonlinear dynamics regime are reviewed. 相似文献